Alpha-acylvinylthioethers



Unted States Patent 3,305,588 oz-ACYLVINYLTHIOETHERS Alfred A. Schleppnik, St. Louis, Mo., assiguor to Monsanto Company, St. Louis, M0., a corporation of Delaware N0 Drawing. Filed Sept. 17, 1965, Ser. No. 488,277 a Claims. (Cl. 260590) This invention relates to thioethers, more particularly it relates to novel a-acylvinylthioethers.

These new ot-acylvinylthioethers, useful as metal cleaners and polar solvents can be prepared by reacting, under controlled conditions, suitable thioether ketones with suitable aldehydes. These novel compounds are represented by the formula wherein R is alkyl containing from 1 to 8 carbon atoms, R is selected from the group consisting of alkyl containing 1 to 8 carbon atoms, phenyl and lower alkyl phenyl and R" is selected from the group consisting of alkyl containing 1 to 8 carbon atoms, phenyl and lower alkyl phenyl and the chloro, bromo, nitro, lower alkoxy and di(lower alkyl) amino derivatives of both said phenyl and said lower alkyl phenyl. It is to be noted that, as used herein, lower alkyl means alkyl containing up to 4 carbon atoms.

The thioether ketones which are useful in the preparation of these novel compounds are represented by the formula wherein R and R have the same meaning as described above; that is, R and R" can each be, for example, a straight or branched chain alkyl such as methyl, ethyl, propyl, isopropyl, n-butyl, tert.-butyl, 2-ethylhexyl, n-octyl, Z-methylheptyl and the like. Additionally R can be phenyl or lower alkyl phenyl such as tolyl, cumyl, xylyl and the like.

Compounds which are illustrative of said useful thioether ketones are 1-ethylthi0-2-propanone, l-phenylthio-Z- propanone, 1-ethylthio-2-butanone, 2-phenylthio-3-heptanone, 2-methylthio-3-octanone, 1-n-butylthio-2-octanone, 1-tolylthio-2-propanone, 2-tert.-butylthio-3 hexanone, 3- cumylthio-4-octan0ne, l-xylylthio-Z-propanone and the like.

The aldehydes which are useful in the preparation of the novel wacylvinylthioethers are represented by the formula RCHO wherein R" is as described as above; that is, R" can be a straight or branched chain alkyl, such as methyl, ethyl, propyl, tert.-butyl, pentyl, Z-methylpentyl, n-octyl, 2-ethylhexyl and the like. Additionally, R" can be phenyl or lower alkyl phenyl, such as tolyl, cumyl, xylyl and the like. Furthermore, R" can be the chloro, bromo, nitro, lower alkoxy and di(lower alkyl) amino derivatives of said phenyl and lower alkyl phenyl, such as nitrophenyl, chlorophenyl, bromophenyl, methoxyphenyl, nitrotolyl, chlorocumyl, dimethylaminophenyl, bromoxylyl, bromotolyl, nitrotolyl, methoxytolyl and the like.

Compounds which are illustrative of said useful aldehydes are acetaldehyde; isobutyraldehyde; 2,2-dimethylbutyraldehyde; propionaldehyde; butyr aldehyde; benzaldehyde; p-nitrobenzaldehyde; p-methoxybenzaldehyde;

p chlorobenzaldehyde; o dimethylaminobenzaldehyde; p-bromobenzaldehyde; o-chlorobenzaldehyde; o-methoxybenzaldehyde; p-tolu-aldehyde, cumaldehyde; and the like.

To prepare the compounds of this invention by reacting the suitable thioether ketones with the suitable aldehydes, it is necessary to effect intimate contact in the presence of a suitable catalytic base. The intimate contact is achieved by preparing a solution of the reactants in a suitable solvent. In general, when aromatic aldehydes are used, that is, when R" is other than alkyl, an inert aromatic solvent, such as benzene, toluene, xylene or the like, is preferred. When aliphatic aldehydes are used, that is, when R" is alkyl, aliphatic alcohols, such as methanol, ethanol, propanol and the like, have been found to possess suitable solvent properties and are therefore generally preferred. Although the foregoing solvents are preferred for minimum cost and ease of handling, any material which will dissolve the reactants and the catalytic base, and which does not react with either the reactants or the catalytic base, can be used.

As was mentioned previously, it is necessary to use a catalytic base when preparing the u acylvinylthioethers of this invention. It has been found that when the aromatic aldehydes are used, suitable catalytic bases include piperidine, lower alkyl piperidine and the di(lower alkyl) amines. Compounds illustrative of said useful catalytic bases include piperidine, dimethylpiperidine, ethylmethylpiperidine, methylpiperidine, propylpiperidine, dimethylamine, diethylamine, dibutylamine, di-isopropylamine and the like.

When aliphatic aldehydes are used, it has been found that suitable catalytic bases include the lower alkoxides of sodium and potassium. Compounds illustrative of said useful catalytic bases include sodium ethoxide, potassium ethoxide, sodium methoxide, sodium butoxide, potassium butoxide and the like.

The following non-limiting examples illustrate the preparation of the novel compounds of this invention. All parts, percentages and proportions are by weight unless otherwise indicated.

EXAMPLE 1 3-plzerzylthi0-4-phenylbut-3-ene-2-0ne A solution of about 16.6 grams of 1-phenylthio-2-pro panone, 10.6 grams of benzaldehyde, 1.0 gram of piperidine and 1.0 gram of acetic acid in about 43.0 grams of toluene is prepared. The solution is refluxed and the theoretical amount of water is collected. Distillation of the crude material by a short path apparatus gives 25.2 grams of a yellow liquid.

Elemental analysis of the yellow liquid compared to the theoretical content of 3-phenylthio-4-phenylbut-3-ene- 2-one having an empirical formula, C H OS, is given below.

Calculated (percent): Carbon, 75.57; hydrogen, 5.55; sulfur, 12.58. Found (percent): Carbon, 75.08; hydrogen, 5.88; sulfur, 12.64.

Additional analyses by infrared absorption and nuclear magnetic resonance establish the product to be 3-phenylmercapto-4-phenylbut-3-ene-2-one.

EXAMPLE 2 3-phenylthi0-4- (p-nitro phenylbut-3-ene-2-0ne About 7.6 grams of p-nitrobenzaldehyde and about 8.3 grams of l-phenylthio-Z-propanone are dissolved in about 45.0 grams of benzene. After about 0.5 gram of piperidine are added, the mixture is refluxed until the evolution of water ceases. The crude material is fractionally distilled to remove solvent. After solvent removal, a sample of the material, analyzed by standard elemental analyses,

3 is found to be consistent with 3-phenylthio-4-(p-nitro)- phenylbut-3-ene-2-one (empirical formula, C H O NS). Additional analyses by infrared absorption and nuclear magnetic resonance further identify the compound as 3- certain specific embodiments, it is not so limited. It is to be understood that variations and modifications thereof may be made by those skilled in the art without departing from the spirit and scope of the invention.

phenylthio-4-(p-nitro)phenylbut-3-ene-2-one. 5 What is claimed is:

EXAMPLE 3 1. An a-acylvinylthioether of the formula 3-ethylthi0-4-phenylbut-3-ene-2-one A solution of 23.6 grams of 1ethylthio-2-propanone O and 21.2 grams of benzaldehyde in about 160 grams of benzene is prepared. After 1.0 gram of piperidine and 1.0 gram of acetic acid are added to the foregoing solus tion, the mixture is refluxed until the evolution of water ceases. The material is then washed with water and dilute hydrochloric acid and dried over sodium sulfate. Distillation of the washed material affords a product having a boiling range of at 01 Hg pressllfewherein R is an alkyl containing from 1 to 8 carbon Elemental analyses for carbon, hydrogen and Sulfur are atoms, R is selected from the group consisting of alkyl Consistent With 3 ethylthio 4 P Y containing 1 to 8 carbon atoms, phenyl and lower alkyl 12 14 Additional analyses y infrared absorption phenyl and R" is selected from the group consisting of and y nuclear magnetic fesmlance also indicate the alkyl containing from 1 to 8 carbon atoms, phenyl, lower material is Y -P 3 alkyl phenyl and the nuclearly substituted chloro, brorno,

EXAMPLE 4 nitro, lower 'alkoxy and di(l0wer alkyl) amino derivatives of both said phenyl and said lower alkyl phenyl. 3ethylthmpent'3'ene'z'one 2. An u-acylvinylthioether of claim 1 wherein R is About 23.6 grams of l-ethylthio-Z-propanone and about P y 10 grams of acetaldehyde are dissolved in about 70 milli- All a-acylvinylthioethef of claim 1 Whefein is liters of ethanol. To the foregoing solution, about 3.0 p y grams of a 1 normal solution of sodium ethoxide in ethari- An a-acylvinylthioethef Claim 1 wherein 01 are added. After an exothermic reaction has occurred, are each ph nyl distillation of the crude material at 3 mm. Hg pressure AH wficylvinylthioethef f Claim 1 'W r n is yields a compound having a boiling range of 4447 C. at alkyl containing 1 to 8 carbon atoms, 0.4 mm. Hg pressure. Using the analytical techniques of An w-acylvinylthi-oether of claim 1 wherein R" is Examples 1, 2 and 3, the compound is identified as 3-ethylalkyl containing 1 to 8 carbon atoms, thi0pent-3-ene-2-one having an empirical formula, 7. An ot-acylvinylthioether of claim 1 wherein R and (3 1-1 05, R are each alkyl containing 1 to 8 carbon atoms.

Other oc-EICYlVlIlYlthiOBihGI'S are prepared using the same An -acylvinylthiocther of claim 1 wherein R is procedures as in Examples 1, 2, 3 and 4. Selected nonphenyl and R" is alkyl containing 1 to 8 carbon atoms. limiting examples of these novel compounds are shown 9. An a-acy y of Claim 1 h r in R i in the following table. alkyl containing 1 to 8 carbon atoms and R" is phenyl. TABLE Example Reactants Qat alytic Base a-Aeylvinylthioether 5 l-n-butylthio-2-butanone propionaldehyde Sodium cthoxide 4-n-butylthiohcpt-4-e11e-3-0ne.

l-methylthio-2-heptanone p-methcxybenzaldehyde Piperidine 2methylth 1o-1-(p-me thoxyphenyl)-oct-2-ene-3-one. lkil-tgleylthioa-butanone dimethylaminohenzaldc- Diethylamine Zlglglggillllew-l-l'(0-dlmethylaminophenyl)-pcut-2- l-m cumylthio-z-propanone p-chl0robenzaldehyde Dimethy1amine 2m-cumylt hio-l-(p-ehlorophenyl)-but-3-cne-3-one. l-phenylthio-2-butanone p-tolualdehyde Dibutylamine 2-phenylthio-l-p-toly1pent-2-ene-3-one. l-n-propylthio-Z-propanone xylylaldehyde Dimethylpiperid 2- -pr0pylthio-l-xylyl-but-Z-ene-Sene. l-tert-butylthio-2-hexan0ne 2-chloro-p-tolyl-alde- Piperidine 2-tert-butylthio-1-(z-chloro-p-tolyl)-hept-2-ene-3-onc.

hyde. l-xylylthio-Z-pentanone p-cumaldehyde. l-phenylthio-Zpctanone bntyraldehyden 3-rnethyl-l-ethylthio-Z-pentanone propionaldehyde- Di-isopropylamine Potassium methoxide.

Sodium butoxide I l-isopropylthio-Z-pentanone isobu tyraldehyde Sodium ethoxide 2-1110thyl i-isopropylthio-oct-4-ene-5-0ne. lethylthio-2-propanone octylaldehyde Piperidine. 3-ethylthio dodec-3-ene-2-one. l-methylthio-Z-heptanone p-hromobenzaldehyde. do t YIthIO- -(p-bromophenyD et-2-ene-3-one. 1-p-t0lylthi0-2-hexanone p-nitrob enzaldehyde Ethylmethylpiperidma- 2-p-t0lylth1o-1-(p-nitrophenyl) -hept 2-ene-3-one. l-mesitylthio-Z-butanone acetaldehyde Potassium ethoxide 3-mesitylth1o-hex-3-ene-4-one.

l-n-propylthio-Z-hexanone henzaldehyde Dimethylamine Z-n-propylthlo-l-pheuylhept-2-ene3-one.

The m-acylvinylthioethers of this invention have prop- 3 cities which make them useful as intermediates in organic synthesis, as metal cleaners, and as polar solvents.

While the invention has been described with regard to No references cited.

LEON ZITVER, Primary Examiner. DANIEL D. l-IQRWITZ, Examiner, 

1. AN A-ACYLVINYLTHIOETHER OF THE FORMULA 